Patent GB-836880-A (GB)
Title: Improvements in machine for casting printing plates
IPC: B41D3/04
Filed: 1956-03-27
Abstract: 836,880. Stereotype casting apparatus. WOOD NEWSPAPER MACHINERY CORPORATION. March 27, 1956 [June 2, 1955], No. 9536/56. Class 100(2) [Also in Group XXVIII] A stereotype plate casting apparatus has a casting section and a trimming section, the casting section comprising a vertical mould having a core mounted for movement from a vertical to a horizontal position, and the trimming section comprising a trimming arch and plate supporting tracks within the arch. Tracks are provided at the side of the movable core section and a positioner to engage the edge of the plate when the core section is opened. Finch tracks are provided between the trimming and casting sections. Stereotype plate casting apparatus As shown the machine includes a pump 1 (Fig. 3) having a cylinder 2 in which operates a piston 4 connected with lost motion to a piston rod 5. The rod 5 is provided with a disc 6 so that ports 8 in the piston 4 are closed as the piston rises, thus forcing molten metal from the furnace 3 through a discharge passage 9, and opened as the piston descends to allow molten metal to flow through the ports 8 into cylinder 2. The piston 4 is actuated by compressed air supplied to a cylinder 16 supported at the upper end of the rod 5. The supply of air is controlled by a solenoid operated valve 21. The rod 5 is provided with pins 27 for pivoting an arm 26 about a shaft 25. Fixed on the shaft 25 is a member 28 which also carries a pin 31 for engaging a switch 32 on the arm 26. The arm 26 is connected to the member 28 by a spring 33. In the position shown in Fig. 3 when the valve 21 is operated by its solenoid the rod 5 rises and rotates the arm 26 and member 28 until the latter contacts an adjustable stop pin 29, whereupon further upward movement of the rod 5 causes the arm 26 to move relatively to the member 28 so that the switch 32 is operated to break the circuit to the solenoid operating the valve 21 and the piston 5 begins to descend. The molten metal is forced by the pump through the passage 9 to a discharge port 14 (Fig. 8) for delivery between a fixed mold section 12 and a movable section 65. The section 12 (Fig. 11a) is double-walled and vertically mounted on a frame casting 11 through which water is circulated by pipes 40 and 41. Thermostats are provided for controlling the temperature of the water. The front face of the . section 12 is double-walled to provide a vacuum chamber 44 in which perforations are provided for holding the matrix against the mold section 12. The chamber 44 communicates with a pipe 47 connected to a vacuum pump. A pouring shield 50 is provided mounted in hangers 52 rotatable about a shaft 59. The shield 50 is biased by springs 62 to the position shown in dotted lines in Fig. 8 and is held in operative position when the movable mold section 65 is in position by brackets 58 on the mold section 65 which engage behind bolts 57 on the hangers 52. The brackets 58 also engage arms 15a on a pivoted cutoff lip 15 for the spout 14 so that the lip 15 is held out of spout covering position when the mold section 65 is positioned for casting. The movable mold section 65 also comprises a double-walled casting having water connections 66 and thermostats 42a. When in closed position the weight of the mold rests on a semi-circular ring 91 pivoted at its ends on shafts 92. The ring section may be pivoted by depressing a foot pedal 94 (Fig. 12) connected to a shaft 95 which, on rotation, pivots the ring 91 through links 96, 97. The section 65 is provided with rollers 70 running on guides 71 and with arms 80 pivoted to the machine frame and to the mold section so that after casting the section 65 may be moved to a horizontal position. To move the mold section 65 a handle 73 is provided, depression of which raises a bar 83 to which locking bars 75 are connected by links 85. The bars 75 engage members 81 and 82 on the mold section 12 (Fig. 14) when in operative position, but on depression of the handle 73 they are drawn inwardly to release the mold sections. After the mold sections have been released the section 65 is moved to horizontal position by pulling on lever 73 and operating the pedal 94. The rear face of the section 65 is provided with a removable cover 100 and also with side bearing plates 101 which serve as rests for the section when in open position. A pair of adjustable matrix positioning plates 105 are provided on the fixed section 12 to hold the matrix in position until the movable section is closed. A switch 87, operable by the bar 83, is provided and is such that a casting operation cannot be initiated until the switch 87 is) operated by closure and locking of the mold sections 12 and 65. An electric control circuit (Fig. 35, not shown) is provided for the metal pump to ensure that the operator cannot make a second pour with the mold closed and after the mold has been opened a second pour cannot be made until the plate is removed, the matrix repositioned, and the core closed. Plate shaving and trimming mechanism. When the mold section 65 together with a cast plate has been moved to its horizontal position, the operator removes the matrix and shifts the cast plate along guide rails to the shaving and trimming section. The section includes a shaft 106 driving by belts and worm wheels and worm gears from a motor 103. The shaft 106 carries a coarse shaving cutter 115 (Fig. 24) and a fine shaving cutter 116. Through the shaft 106 is mounted a shaft 107 (Fig. 18) which through gearing 108, 122 drives a trimmer 121. A guide member 130 is adjustably mounted on the shaft 106 and is such that as the plate is drawn into the shaving and trimming section the guide pivots anticlockwise as viewed in Fig. 11b until it is cleared by the trailing edge of the plate, whereupon it springs back into upright position and the plate is then pushed back against it. The guide is provided with a bevelled edge 138 so that when the shaft 106 begins to rotate, if the plate has been indented by the face by which it has been pushed against the guide, the plate is repositioned in its proper position by engagement of the bevelled edge with the unindented portion of the plate. The plate is positioned on guides 124, 125 (Fig. 27) the frame of which is stationary. The guide 125 is such that it can move upwardly to hold the plate against a cylindrical casting 120 as shown in Fig. 25. The guide 125 is operated by a cam 140, on the shaft 106, which co-operates with a cam follower 142 fixed on a bifurcated arm 141 so that as the cam 140 rotates the arm 141 is forced downwardly so that by means of an arm 145 a shaft 146 is rotated anticlockwise. Two arms 147 are keyed to the shaft 146, each of which carries a pivot pin 168 through which extends a rod 1'58, to the upper end of which is attached a bar 155 supporting the guide 125. The bar 155 slides in guides 156 pivoted to arms 157 supported on the shaft 146. The guides 156 have arms 164 carrying rollers 163 spring biased against a cam portion of the arms 147. A spring 160 surrounds each rod 158 and it is through the medium of the spring that the arms 147 lift the bars 155. The arrangement of the cams is such that as shaft 106 rotates the bars 155 are moved upwardly and outwardly to position the plate against the casting 120 and hold it there during shaving and trimming by the pressure exerted by the springs 160 and 165. After the shaving and trimming operation, the guide 125 is again lowered by the action of the cam 140, a stop switch being provided on the main shaft 106 to cut off the motor 103. The cut plate is then positioned by the operator on guides 201 of a cooling section, the guides 201 being in line with guide 202 leading from the trimming section (Fig. 33). The cooling section comprises a series of spray pipes 203 extending from a manifold 204 which is supplied with water from pipes 205 and with compressed air from a pipe 219. Supported beneath the manifold is a shaft 206 to which semicircular cover sections 207 (Fig. 30) are attached. A coil spring 208 (Fig. 11b) is provided so that the covers are biased to a position below the shaft 206, i.e., in an anti-clockwise direction as viewed in Fig. 30. A handle 214 is provided for positioning the covers in operative position against the action of the spring 208. The covers are held in position by means of a latch 217 which engages a notch 216 on a disc 215 fast on the shaft 206. The latch may be released manually or by means of a solenoid at the end of the cooling operation, so that the covers return under the action of the spring 208 to inoperative position. Trips 210, operable by the leading edges of a plate to be cooled are provided and are such that until a plate is properly positioned closure of the covers 207 is impossible.